1. Field of the Invention
The present invention relates to an image sensor used for an image input device and in particular, to a contact type image sensor in which a plurality of semiconductor chips are mounted as a photoelectric conversion element and also to a manufacturing method thereof.
2. Description of the Related Art
As one configuration of a linear image sensor of a multi-chip type in which a plurality of semiconductor chips each formed by arranging many photoelectric conversion elements (image pick-up elements) with a constant interval therebetween are arranged linearly, FIGS. 5 and 6 of JP-A-2005-295095 discloses the configuration in which, in order to interpolate a state (also called as an imaginary image pickup element) that there is no image pickup element at a gap region between the adjacent semiconductor chips, a transparent plate having a refraction function is provided at an optical path region corresponding to the boundary area of the semiconductor chips thereby to incident light dividedly to the image pickup elements of the adjacent semiconductor chips.
An image reading device is disclosed in FIG. 9 of a JP-A-2003-101724, in which a plurality of chips are arranged so as to prevent a density difference caused by a pitch error between the chips (at a boundary of the chips) from becoming conspicuous. In the drawing, reference symbols C1 and C2 denote chips (photoelectric conversion elements), Ca and Cb denote chip ends adjacent to each other, La denotes a gap distance between the ends of adjacent chips. Further, a reference symbol r denotes an image pickup element (light receiving element), P denotes a distance between the image pickup elements, P′ denotes a distance between boundary image pickup elements. Still further, in FIG. 3(c) of JP-A-2003-101724, reference symbols C14 and C21 are image pickup elements located at the boundary of the chips adjacent to each other.
Moreover, FIG. 4 of JP-A-6-218985 discloses an image reading device in which a plurality of optical element chips are arranged. In the drawing, a reference symbol 1 denotes an optical element chip, 2 denotes an element (light receiving element), 3 denotes an (inclined) end surface in a longitudinal direction, 3a denotes an edge on the main surface side of the chip 1, 3b denotes an edge on the rear surface side (substrate side) of the chip 1, 7 denotes a substrate, and 8 denotes silver paste.